1. Field of the Invention
The present invention relates to an inspecting apparatus for comparing a pattern, formed by an opaque material such as chromium on a radiation-transmitting substrate, of a mask or a reticle employed in the manufacture of semiconductor devices (hereinafter collectively called mask) with design data of said pattern.
2. Related Background Art
A mask is currently prepared by individual exposures of different patterns on different areas of a substrate, and design data of plural patterns formed in the mask are recorded on a recording medium such as a magnetic tape. According to the purpose, the pattern indicated by the design data can be either positively or negatively exposed by changing the characteristics of the photoresist to be coated on the substrate. In the case of a negative exposure, on the substrate, of a pattern based on certain design date, the exposed pattern is an inversion of the original design data so that the pattern formed on the mask is different from the design data recorded on the recording medium. Also a simple pattern inversion of the design data requires a long processing time on a computer.